Fuel filters of internal combustion engines, in particular in the automotive field, include a filter housing with a housing base body and at least one lid. Frequently, the housing base body is comprised of cast metal, in particular die cast aluminum or the like. The mechanically less loaded lid may be comprised of plastic material and is screwed by means of screws to the housing base body. Between the lid and the housing base body a lid seal is arranged in order to make the mounted filter housing fuel-tight in operation.
According to the prior art, the cast metal blank of the housing base body is mechanically processed (machined) at least in the area of the screw receptacles for the lid screws and at the sealing seat of the lid seal. A thread is cut into the screw receptacles. The seal seat is turned to size for which purpose material allowance of approximately 1 mm is required on the cast blank. The step of chip-producing after machining of the cast blank requires cost-intensive working steps. The material allowance in the area of the surfaces to be machined increase the material costs. The finished fuel filters are subject to high requirements in particular with respect to cleanliness as a protection from foreign bodies in the fuel path. After the machining step (cutting), there is therefore an intensive rinsing process required for cleaning the machined housing base body; this represents an undesirable and significant cost factor.
It is therefore an object of the present invention to further develop a fuel filter of the aforementioned kind such that the requirements with regard to clean components can be fulfilled with simple means and high processing safety.